Image sensor and method for manufacturing image sensor

ABSTRACT

There is provided an image sensor including: a light polarizing unit configured to transmit light in a specific light polarization direction out of incident light; a pixel configured to generate an image signal corresponding to the light transmitted through the light polarizing unit; and a signal transfer unit formed simultaneously with the light polarizing unit and configured to transfer either of the image signal and a control signal that controls generation of the image signal.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is continuation of and claims priority to U.S.application Ser. No. 16/478,597, filed Jul. 17, 2019, which is anational stage application under 35 U.S.C. 371 and claims the benefit ofPCT Application No. PCT/JP2018/007769 having an international filingdate of Mar. 1, 2018, which designated the United States, which PCTapplication claimed the benefit of Japanese Priority Patent ApplicationNo. 2017-098622 filed on May 18, 2017, the disclosures of each of whichare incorporated herein by reference.

TECHNICAL FIELD

The present technology relates to an image sensor. Specifically, thepresent technology relates to an image sensor including a lightpolarizing unit that transmits light in a specific light polarizationdirection and a method for manufacturing the image sensor.

BACKGROUND ART

Thus far, an image sensor in which light polarization information ofincident light is acquired by placing, for each pixel, a lightpolarizing unit that transmits light in a specific light polarizationdirection and performing photoelectric conversion has been used. Byacquiring the light polarization information, the three-dimensionalshape of the object can be easily grasped, for example. This is becausethe reflected light from the object is polarized in directions differentbetween surfaces of the object, and therefore the shape of the surfaceof the object can be easily acquired by performing imaging whileselecting light polarization directions. Further, an image sensor usedfor a monitoring device or the like can be used in order to remove animage appearing on a windshield of a vehicle undesirably. This isbecause the image appearing on the windshield of the vehicle undesirablyis strongly optically polarized in a specific direction, and can beeasily removed by acquiring light polarization information. Alightpolarizing unit configured with a wire grid is used as such a lightpolarizing unit. This is a light polarizing unit configured with aplurality of lines arranged with a pitch narrower than the wavelength ofincident light.

As a method for manufacturing an image sensor including such a lightpolarizing unit, for example, a method for manufacturing an image sensorin which a light polarizing unit is formed on a support substrate, thenthe light polarizing unit on the support substrate is transferred to anupper portion of a photoelectric conversion unit that performsphotoelectric conversion, and thereby a light polarizing unit is formedis used. In this manufacturing method, an oxide film is formed on thesurfaces of the photoelectric conversion unit and the light polarizingunit and these oxide films are stuck together, and thereby thephotoelectric conversion unit and the support substrate are adheredtogether. After that, the support substrate is removed, and thereby animage sensor including a light polarizing unit is formed (e.g., see PTL1).

CITATION LIST Patent Literature

-   [PTL 1]-   JP 2012-142501A

SUMMARY Technical Problem

The existing technology described above has a problem that themanufacturing process is complicated because a light polarizing unitformed on a different substrate is transferred to a photoelectricconversion unit.

Thus, it is desirable to simplify the manufacturing process of an imagesensor including a light polarizing unit that transmits light in aspecific light polarization direction.

Solution to Problem

According to an embodiment of the present technology, there is providedan image sensor, comprising: a plurality of pixels, each pixelincluding: a photoelectric conversion unit; a light polarizing unit; apixel circuit; and a plurality of signal transfer units, wherein atleast a portion of the light polarizing unit and at least a portion ofthe signal transfer units are at a same layer of the image sensor.

According to another embodiment of the present technology, there isprovided an image sensor, comprising: a substrate; a photoelectricconversion unit formed in the substrate; a light polarizing unit on alight incident side of the substrate; and a signal transfer unit on thelight incident side of the substrate, wherein the light polarizing unitand the photoelectric conversion unit are formed at a same layer of theimage sensor.

According to still another embodiment of the present technology, thereis provided a method of forming an image sensor, comprising: providing asubstrate; forming a first flattening film on a light incident side ofthe substrate; forming a light blocking material on the first flatteningfilm; and forming a plurality of light blocking lines and at least afirst signal transfer unit from the light blocking material.

Advantageous Effects of Invention

According to an embodiment of the present technology, an excellenteffect of simplifying the manufacturing process of an image sensorincluding a light polarizing unit that transmits light in a specificlight polarization direction is exhibited.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing an example of the configuration of an imagesensor according to a first embodiment of the present technology.

FIG. 2 is a schematic cross-sectional view showing an example of theconfiguration of an image sensor according to the first embodiment ofthe present technology.

FIG. 3 is a diagram showing an example of the method for manufacturingan image sensor according to the first embodiment of the presenttechnology.

FIG. 4 is a diagram showing an example of the method for manufacturingan image sensor according to the first embodiment of the presenttechnology.

FIG. 5 is a diagram showing an example of the method for manufacturingan image sensor according to the first embodiment of the presenttechnology.

FIG. 6 is a diagram showing an example of the method for manufacturingan image sensor according to the first embodiment of the presenttechnology.

FIG. 7 is a schematic cross-sectional view showing an example of theconfiguration of an image sensor according to a first modificationexample of the first embodiment of the present technology.

FIG. 8 is a diagram showing an example of the configuration of an imagesensor according to a second modification example of the firstembodiment of the present technology.

FIG. 9 is a schematic cross-sectional view showing an example of theconfiguration of an image sensor according to a second embodiment of thepresent technology.

FIG. 10 is a diagram showing an example of the configuration of an imagesensor according to a third embodiment of the present technology.

FIG. 11 is a diagram showing an example of the configuration of an imagesensor according to a fourth embodiment of the present technology.

FIG. 12 is a schematic cross-sectional view showing an example of theconfiguration of an image sensor according to a fourth embodiment of thepresent technology.

FIG. 13 is a schematic cross-sectional view showing an example of theconfiguration of an image sensor according to a fifth embodiment of thepresent technology.

FIG. 14 is a diagram showing an example of the configuration of animaging device according to an embodiment of the present technology.

FIG. 15 is s diagram showing an example of the configuration of a pixelcircuit according to an embodiment of the present technology.

FIG. 16 is a diagram illustrating an example of a schematicconfiguration of an endoscopic surgery system.

FIG. 17 is a block diagram illustrating an example of a functionalconfiguration of the camera head and the CCU.

FIG. 18 is a block diagram showing an example of the schematicconfiguration of a vehicle control system.

FIG. 19 is an explanatory diagram showing an example of the installationposition of a vehicle outside information detection unit and an imagingunit.

DESCRIPTION OF EMBODIMENTS

Next, embodiments for implementing the present technology (hereinafter,referred to as embodiments) are described with reference to thedrawings. In the following drawings, identical or similar portions aremarked with identical or similar reference signs. However, the drawingsare schematic ones, and the proportions of dimensions, etc. of portionsdo not necessarily coincide with the actual ones. Further, portions forwhich the relationships of dimensions and the proportions are differentamong drawings may be included in the drawings, as a matter of course.Further, the embodiments are described in the following order.

-   -   1. First Embodiment    -   2. Second Embodiment    -   3. Third Embodiment    -   4. Fourth Embodiment    -   5. Fifth Embodiment    -   6. Sixth Embodiment    -   7. Application example to endoscopic surgery system    -   8. Application example to mobile object

1. First Embodiment

Configuration of Image Sensor

FIG. 1 is a diagram showing an example of the configuration of an imagesensor according to a first embodiment of the present technology. Animage sensor 1 of the drawing includes a pixel array unit 10, signaltransfer units 20, and interconnections 30.

The pixel array unit 10 is configured by pixels 100 being arranged in atwo-dimensional lattice form. Here, the pixel 100 generates an imagesignal corresponding to the applied light. As described later, the pixel100 includes a photoelectric conversion unit that generates a chargecorresponding to the applied light. Further, the pixel 100 furtherincludes a pixel circuit. The pixel circuit generates an image signalbased on the charge generated by the photoelectric conversion unit. Thegeneration of the image signal is controlled by a control signalinputted from the outside of the image sensor 1. The photoelectricconversion unit and the pixel circuit are formed in a semiconductorsubstrate. In addition, in the drawing, the circle written by the dottedline represents an on-chip lens 121. The on-chip lens 121 is a lens thatis placed for each pixel 100 and forms, on the photoelectric conversionunit, an image of light incident on the pixel 100.

Further, the pixel 100 further includes a light polarizing unit 110. Thelight polarizing unit 110 transmits light in a specific lightpolarization direction. A light polarizing unit configured with a wiregrid may be used as the light polarizing unit 110, for example. Here,the light polarizing unit configured with a wire grid is a lightpolarizing unit configured with a plurality of lines arranged with apitch narrower than the wavelength of incident light. The plurality oflines are configured with a material having the property of absorbing orreflecting light, and perform the blocking of light. Hereinafter, theline configuring the light polarizing unit 110 is referred to as a lightblocking line. The light blocking line may be configured with, forexample, a metal such as aluminum (Al). By arranging a plurality oflight blocking lines with a pitch narrower than the wavelength ofincident light, light perpendicular to the arrangement direction of theplurality of light blocking lines can be attenuated. On the other hand,light parallel to the arrangement direction of the plurality of lightblocking lines passes through the light polarizing unit 110 withoutbeing attenuated. Thus, the light polarizing unit 110 can transmit lightin a specific light polarization direction.

As shown in the drawing, the plurality of light blocking lines of thelight polarizing units 110 may be formed to be arranged in directionsdifferent between pixels 100. In the drawing, light polarizing units 110of which the direction is shifted by 45 degrees between adjacent pixels100 are formed. Thus, light polarization information of light incidenton the image sensor 1 can be acquired by causing image signals to beoutputted from the pixels 100 including the light polarizing units 110arranged in different directions. In addition, the configuration of thelight polarizing units 110 is not limited to this example. For example,light polarizing units 110 of a configuration in which the direction isshifted by an angle other than 45 degrees between adjacent pixels 100are possible.

The signal transfer unit 20 transfers either of the image signal and thecontrol signal described above. A plurality of signal transfer units 20are arranged in a peripheral portion of the image sensor 1; and transfera control signal inputted from the outside of the image sensor 1 to thepixel 100, and transfer an image signal generated by the pixel 100 to aprocessing apparatus outside the image sensor 1. A pad configured withthe same metal as the light blocking line of the light polarizing unit110 may be used as the signal transfer unit 20. As described later, thesignal transfer unit 20 is formed simultaneously with the lightpolarizing unit 110 in the manufacturing process of the image sensor 1.

The interconnection 30 is placed between the signal transfer unit 20 andthe pixel 100, and transfers signals between the signal transfer unit 20and the pixel circuit formed in the semiconductor substrate. Theinterconnection 30 is placed near the light polarizing unit 110.Similarly to the signal transfer unit 20, the interconnection 30 may beconfigured with the same metal as the light blocking line of the lightpolarizing unit 110, and can be formed simultaneously with the lightpolarizing unit 110 in the manufacturing process of the image sensor 1.

FIG. 2 is a schematic cross-sectional view showing an example of theconfiguration of an image sensor according to the first embodiment ofthe present technology. The drawing is a diagram showing a cross sectionof the image sensor 1 taken along line A-A′ in FIG. 1 . The pixel 100 ofthe drawing includes, in addition to the on-chip lens 121 and the lightpolarizing unit 110, a color filter 122, a photoelectric conversion unit132, an interconnection layer 142, and an insulating layer 141.

The color filter 122 is an optical filter that transmits light of aprescribed wavelength. The color filter 122 can transmit, for example,red light, green light, or blue light out of the light formed as animage by the on-chip lens 121. Pixels 100 in which color filters 122that transmit red light, green light, and blue light are arranged may beconfigured in a prescribed array, such as the Bayer array. Further, acolor filter 122 corresponding to light of the same wavelength may beplaced in four pixels that include light polarizing units 110 of whichthe direction is shifted by 45 degrees between adjacent pixels 100.Specifically, it is also possible to employ a configuration in which acolor filter that transmits red light, green light, or blue light isplaced in pixels 100 of two rows by two columns in FIG. 1 as a unit. Inaddition, the color filter 122 may be a color filter that transmitsanother color, such as a color filter corresponding to white light thatcan transmit red color to blue color.

The light polarizing unit 110 of the drawing is configured by aplurality of light blocking lines 111 being arranged at equal intervals.A material of the property of transmitting light may be used for an area112 between light blocking lines 111. In the light polarizing unit 110of the drawing, the area 112 is filled with air. The plurality of lightblocking lines 111 and the plurality of areas 112 are configured with anequal line-and-space, and transmit light in a specific lightpolarization direction. Further, a protection film 124 is formed on aside of the light blocking line 111 and the area 112 on which light isincident. The protection film 124 protects the light polarizing unit110, and hermetically seals the area 112. Silicon oxide (SiO₂) andsilicon nitride (SiN) may be used as the protection film 124. Further, asecond flattening film 123 is formed between the protection film 124 andthe color filter 122. SiO₂, an acrylic resin, or spin-on glass (SOG) maybe used for the second flattening film 123.

The photoelectric conversion unit 132 is formed in a semiconductorsubstrate 131. The photoelectric conversion unit 132 is configured witha semiconductor of a different type from the semiconductor substrate131. For example, the semiconductor substrate 131 and the photoelectricconversion unit 132 may be configured as a p-type semiconductor and ann-type semiconductor, respectively. If light transmitted through thelight polarizing unit 110 is incident on a p-n junction area formed atthe interface between the semiconductor substrate 131 and thephotoelectric conversion unit 132, a charge based on photoelectricconversion is generated. Thus, the photoelectric conversion unit 132 andthe semiconductor substrate 131 configure a photodiode. The chargegenerated by the photodiode is converted to an image signal by the pixelcircuit (not illustrated) placed in the vicinity of the photoelectricconversion unit 132, and is outputted from the pixel 100. A firstflattening film 125 is formed between the semiconductor substrate 131and the light polarizing unit 110. The first flattening film 125 may beconfigured with SiO₂.

The image signal generated in the pixel 100 and the control signal thatcontrols the pixel circuit of the pixel 100 are transferred by theinterconnection layer 142. The interconnection layer 142 is formed inthe interior of the insulating layer 141 that is formed adjacent to asurface of the semiconductor substrate 131 different from the surface onwhich light is incident. An image sensor in which light is thus appliedto the photoelectric conversion unit 132 from a surface of thesemiconductor substrate 131 on the back side of the surface on which theinterconnection layer 142 is formed is called a back-side illuminationimage sensor. In addition, the interconnection layer may be configuredwith a metal.

The interconnection 30 of the drawing is placed on the same surface ofthe image sensor 1 as the light blocking line 111 of the lightpolarizing unit 110, and the protection film 124 is formed on thesurface. Further, the interconnection 30 of the drawing extends to anarea of the signal transfer unit 20, and configures a part of the signaltransfer unit 20. A part of the interconnection 30 configuring a part ofthe signal transfer unit 20 is referred to as a first signal transferunit 21. The interconnection 30 and the interconnection layer 142 areconnected together by a via plug 32. The via plug 32 may be configuredwith a metal.

In addition, the interconnection 30 is formed in the vicinity of thelight polarizing unit 110. As described later, the light blocking line111 of the light polarizing unit 110 is formed by dry etching. The dryetching enables directional etching, and is therefore an etching methodthat can be used at the time of forming a fine pattern like the lightpolarizing unit 110. However, in dry etching, a phenomenon in which theetching rate varies with the roughness and fineness state of the patternto be formed is known. This phenomenon is called as a micro-loadingeffect, and is a cause of failure in etching. Specifically, in an areaof the light polarizing unit 110 where the light blocking line 111 isformed with a narrow pitch, the etching rate is greatly reduced ascompared to other areas. Hence, a remaining balance of etching occurs inthe light polarizing unit 110. Thus, the interconnection 30 is formed inthe vicinity of the pixel array unit 10. Thereby, the roughness andfineness state of the area to be etched can be eased, and the occurrenceof failure in etching can be prevented.

The signal transfer unit 20 of the drawing is configured by the firstsignal transfer unit 21 described above and a second signal transferunit 22 placed adjacent to the first signal transfer unit 21. Further,an opening 23 is formed in the second flattening film 123 adjacent tothe surface of the signal transfer unit 20. A solder ball (notillustrated) is placed on the signal transfer unit 20 facing the opening23, for example. The image sensor 1 is, via the solder ball, connectedto a processing circuit that processes an image signal and a controlcircuit that generates a control signal. Thus, the signal transfer unit20 is connected to circuits outside the image sensor 1; therefore, it isnecessary to improve the mechanical strength of the signal transfer unit20. Hence, the second signal transfer unit 22 is placed to increase thefilm thickness of the signal transfer unit 20, and thereby themechanical strength is improved. In addition, the protection film 124between the first signal transfer unit 21 and the second signal transferunit 22 is removed. This is in order to electrically connect the firstsignal transfer unit 21 and the second signal transfer unit 22. Further,an underlying metal used during the formation of the solder ball may beplaced on the surface of the second signal transfer unit 22.

Method for Manufacturing Image Sensor

FIGS. 3 to 6 are diagrams showing an example of the method formanufacturing an image sensor according to the first embodiment of thepresent technology. The manufacturing process of the image sensor 1 willnow be described using FIGS. 3 to 6 . First, the insulating layer 141and the interconnection layer 142 are formed on the front surface of thesemiconductor substrate 131 in which diffusion layers such as thephotoelectric conversion unit 132 are formed. After that, the rearsurface of the semiconductor substrate 131 is polished to reduce thethickness, an insulating film and an anti-reflection film (notillustrated) are stacked, and then the first flattening film 125 isformed. After that, the via plug 32 is formed. This can be performed byforming a via hole extending from the surface of the first flatteningfilm 125 to reach the interconnection layer 142 and placing a metal in apillar shape in the via hole (a in FIG. 3 ). Next, a light blockingmaterial 29 is formed on the surface of the first flattening film 125.A1 formed by vacuum vapor deposition may be used as the light blockingmaterial 29 (b in FIG. 3 ).

Next, etching is performed on the light blocking material 29 to form aplurality of light blocking lines 111 and a plurality of areas 112. Inthis event, also the interconnection 30 and the first signal transferunit 21 are formed simultaneously. These can be formed by forming aresist on the light blocking material 29 and then performing dry etching(for example, reactive ion etching) to remove areas corresponding to theareas 112 (c in FIG. 4 ). This process corresponds to a light polarizingunit formation process. By this process, the light polarizing unit 110,the interconnection 30, and the first signal transfer unit 21 can beformed simultaneously. In this event, by placing the interconnection 30in the vicinity of the pixel array unit 10, the micro-loading effect canbe suppressed, and the occurrence of etching failure can be prevented.

Next, the protection film 124 is formed on the surfaces of the lightpolarizing unit 110, the interconnection 30, and the first signaltransfer unit 21. This can be performed by sequentially forming SiO₂ andSiN (d in FIG. 4 ). The formation of SiO₂ and SiN can be performed bychemical vapor deposition (CVD).

Next, an opening 28 is formed in the protection film 124. This can beperformed by dry etching (e in FIG. 5 ). Next, the second signaltransfer unit 22 is formed in the area of the opening 28. This can beperformed by forming a film of A1 by vacuum vapor deposition andremoving the area other than the second signal transfer unit 22 by dryetching (f in FIG. 5 ).

Next, the second flattening film 123 is formed, and the opening 23 isformed (g in FIG. 6 ). After that, the color filter 122 and the on-chiplens 121 are formed (not illustrated). Thereby, the image sensor 1 canbe manufactured.

Thus, by simultaneously forming the light blocking line 111 of the lightpolarizing unit 110, the interconnection 30, and the signal transferunit 20, the manufacturing process can be simplified as compared to acase where these are formed individually.

Modification Example 1

Although in the image sensor 1 described above the pixel circuit and thesignal transfer unit 20 are connected together by the interconnection 30and the interconnection layer 142, the interconnection 30 may be omittedand the transfer of signals may be performed by the interconnectionlayer 142.

FIG. 7 is a schematic cross-sectional view showing an example of theconfiguration of an image sensor according to a first modificationexample of the first embodiment of the present technology. In the imagesensor 1 of the drawing, the interconnection 30 is omitted. Further, theinterconnection layer 142 is extended to an area of the signal transferunit 20, and is connected to the first signal transfer unit 21 by thevia plug 32. Also in the image sensor 1 of the drawing, themanufacturing process of the image sensor 1 can be simplified by formingthe first signal transfer unit 21 simultaneously with the light blockingline 111 of the light polarizing unit 110.

Modification Example 2

The image sensor 1 described above is configured such that the lightpolarization direction of the light polarizing unit 110 is differentbetween adjacent pixels. In contrast, pixels 100 including lightpolarizing units 110 having the same light polarization direction may bearranged in two rows by two columns, and with these four pixels as aunit pixel, the light polarization direction may be differentiatedbetween adjacent unit pixels.

FIG. 8 is a diagram showing an example of the configuration of an imagesensor according to a second modification example of the firstembodiment of the present technology. The image sensor 1 of the drawingincludes light polarizing units 110 of which the light polarizationdirection is shifted by 45 degrees between adjacent unit pixels. In thiscase, image signals and light polarization information of red light,green light, and blue light can be acquired for each unit pixel bysetting the color filters of the unit pixel to the Bayer arrayconfiguration. In addition, the color filter may be a color filter thattransmits another color, such as a color filter corresponding to whitelight. Further, the unit pixel may be configured in another array (forexample, three rows by three columns or four rows by four columns).

In addition, the configuration of the image sensor 1 of the firstembodiment of the present technology is not limited to this example. Forexample, it is also possible to employ a configuration in which, in FIG.2 , the second signal transfer unit 22 is omitted and signals aretransferred using only the first signal transfer unit 21 as the signaltransfer unit 20.

As described hereinabove, according to the first embodiment of thepresent technology, the manufacturing process of the image sensor 1 canbe simplified by simultaneously forming the light polarizing unit 110and the signal transfer unit 20.

2. Second Embodiment

The image sensor 1 of the first embodiment described above uses a lightblocking line 111 configured with a single metal or the like. Incontrast, the image sensor 1 of a second embodiment of the presenttechnology differs from the first embodiment in that a light blockingline of a three-layer structure is used.

Configuration of Image Sensor

FIG. 9 is a schematic cross-sectional view showing an example of theconfiguration of an image sensor according to the second embodiment ofthe present technology. The image sensor 1 of the drawing differs fromthe image sensor 1 described in FIG. 2 in that the light blocking line111 is configured by three layers.

The light blocking line 111 of the drawing includes a light reflectinglayer 115, an insulating layer 114, and a light absorbing layer 113. Thelight reflecting layer 115 reflects light. The light reflecting layer115 may be configured with, for example, A1. The light absorbing layer113 absorbs light. The light absorbing layer 113 may be configured with,for example, tungsten (W). The insulating layer 114 is a transparentinsulator, and adjusts the phase of the light reflected by the lightreflecting layer 115. The adjustment of the phase by the insulatinglayer 114 may be performed by setting the phase of the light reflectedby the light reflecting layer 115 to a phase opposite to the phase ofthe light reflected by the light absorbing layer 113. The light of whichthe phase has been adjusted by the insulating layer 114 and the lightreflected by the light absorbing layer 113 are in antiphase, andtherefore both are attenuated by interference. Thereby, the lightblocking ability by the light blocking line 111 can be improved.Further, the insulating layer 114 serves also as an underlayer of thelight absorbing layer 113. The insulating layer 114 may be configuredwith, for example, SiO₂.

In the image sensor 1 of the drawing, the light reflecting layer 115,the interconnection 30, and the first signal transfer unit 21 are formedsimultaneously. Thereby, the manufacturing process of the image sensor 1can be simplified. Further, the light reflecting layer 115 is smaller inthickness than the light blocking line 111 described in FIG. 2 ; thus,it is desirable for the second signal transfer unit 22 to be formedthicker.

Otherwise, the configuration of the image sensor 1 is similar to theconfiguration of the image sensor 1 described in the first embodiment ofthe present technology, and therefore a description is omitted.

As described above, according to the second embodiment of the presenttechnology, the light blocking ability of the light polarizing unit 110can be improved by using a light blocking line 111 of a three-layerstructure. Thereby, the transmission of light other than light in adesired light polarization direction can be prevented, and the accuracyof the acquired light polarization information can be improved.

3. Third Embodiment

In the image sensor 1 of the first embodiment described above, the lightpolarizing unit 110 and the signal transfer unit 20 are insulated. Incontrast, the image sensor 1 of a third embodiment of the presenttechnology differs from the first embodiment in that the lightpolarizing unit 110 and the signal transfer unit 20 are short-circuited.

Configuration of Image Sensor

FIG. 10 is a diagram showing an example of the configuration of an imagesensor according to the third embodiment of the present technology. Theimage sensor 1 of the drawing differs from the image sensor 1 describedin FIG. 1 in that an interconnection 33 is included.

The interconnection 33 is an interconnection that connects the lightpolarizing unit 110 and the signal transfer unit 20. The interconnection33 electrically connects the light polarizing unit 110 and the signaltransfer unit 20. The interconnection 33 of the drawing is configured byone of the interconnections 30 described in FIG. 1 being connected tothe light blocking line 111 of the light polarizing unit 110. Theinterconnection 33 may be connected to, for example, a signal transferunit 20 connected to the ground potential. Thereby, the potential of thelight blocking line 111 becomes the same potential as the signaltransfer unit 20. In the manufacturing of the image sensor 1, the imagesensor 1 is electrified by ionized gas produced when sputtering or thelike is performed. In this event, in a case where the light polarizingunit 110 is insulated, there is a case where charges associated with theelectrification are accumulated in the light polarizing unit 110 andinsulation breakdown is caused, and the image sensor 1 is damaged. Thus,the interconnection 33 is placed to short-circuit the light polarizingunit 110 and the signal transfer unit 20; thereby, the accumulation ofcharges into the light polarizing unit 110 can be prevented, and thebreaking of the image sensor 1 can be prevented. Here, theinterconnection 33 is an example of a connection unit according to anembodiment of the present disclosure.

Otherwise, the configuration of the image sensor 1 is similar to theconfiguration of the image sensor 1 described in the first embodiment ofthe present technology, and therefore a description is omitted.

As described above, according to the third embodiment of the presenttechnology, the breaking of the image sensor 1 in the manufacturingprocess can be prevented by placing the interconnection 33 to preventthe accumulation of charges into the light polarizing unit 110.

4. Fourth Embodiment

The image sensor 1 of the first embodiment described above uses aback-side illumination image sensor. In contrast, the image sensor 1 ofa fourth embodiment of the present technology differs from the firstembodiment in that a front-side illumination image sensor is used.

Configuration of Image Sensor

FIG. 11 is a diagram showing an example of the configuration of an imagesensor according to the fourth embodiment of the present technology. Theimage sensor 1 of the drawing differs from the image sensor 1 describedin FIG. 1 in that a peripheral circuit unit 40 is further included. Theperipheral circuit unit 40 includes the processing circuit thatprocesses an image signal and the control circuit that generates acontrol signal of the pixel circuit, which are described above in thefirst embodiment of the present technology. It is desirable for theimage sensor 1 in the first embodiment of the present technology to beused while being connected to the control circuit and the processingcircuit placed outside. In contrast, the image sensor 1 of the drawingis an image sensor including the processing circuit etc., and canperform the generation of a control signal and the processing of animage signal. The signal transfer unit 20 of the drawing transfers animage signal or a control signal that is passed between the processingcircuit and the control circuit of the peripheral circuit unit 40, andan apparatus outside the image sensor 1, such as an image processingapparatus.

FIG. 12 is a schematic cross-sectional view showing an example of theconfiguration of an image sensor according to the fourth embodiment ofthe present technology. The image sensor 1 of the drawing is configuredby the insulating layer 141 and the interconnection layer 142, the lightpolarizing unit 110, the second flattening film 123, the color filter122, and the on-chip lens 121 being sequentially arranged on a surfaceof the semiconductor substrate 131. An image sensor of such aconfiguration is called a front-side illumination image sensor in whichlight is applied to the front surface of the semiconductor substrate131. Semiconductor elements configuring the peripheral circuit unit 40of the drawing are formed in the semiconductor substrate 131 on theoutside of the pixel array unit 10 (not illustrated), andinterconnections between these semiconductor elements correspond to theinterconnection layer 142 and the via plug 32 of the drawing.

Also in the image sensor 1 of the drawing, the light polarizing unit 110and the first signal transfer unit 21 are formed simultaneously. Inaddition, in the image sensor 1 of the drawing, the interconnection 30includes an interconnection layer of the peripheral circuit unit 40, andthe interconnection layer of the peripheral circuit unit 40 can beplaced in the same layer as the light polarizing unit 110. Aninterconnection layer 143 of the drawing corresponds to a part of theinterconnection of the peripheral circuit unit 40 placed in the samelayer as the light polarizing unit 110. Also the interconnection layer143 can be formed simultaneously with the light polarizing unit 110 andthe first signal transfer unit 21. Thereby, the manufacturing process ofthe image sensor 1 configured as a front-side illumination type can besimplified. Further, the roughness and fineness state of the area to beetched during dry etching can be eased by placing the interconnection(the interconnection layer 143 of the peripheral circuit unit 40) in thevicinity of the light polarizing unit 110.

Further, the image sensor 1 of the drawing shows an example of the casewhere the interconnection 33 described in FIG. 10 is further included.The interconnection 33 connects the light polarizing unit 110 and theinterconnection layer 143 of the peripheral circuit unit 40.

Otherwise, the configuration of the image sensor 1 is similar to theconfiguration of the image sensor 1 described in the first embodiment ofthe present technology, and therefore a description is omitted.

As described above, according to the fourth embodiment of the presenttechnology, also in the front-side illumination image sensor 1, themanufacturing process can be simplified by simultaneously forming thelight polarizing unit 110 and the signal transfer unit 20.

5. Fifth Embodiment

The image sensor 1 of the fourth embodiment described above uses thelight polarizing unit 110 in a front-side illumination image sensor. Incontrast, the image sensor 1 of a fifth embodiment of the presenttechnology differs from the fourth embodiment in that a light blockingunit is further included.

Configuration of Image Sensor

FIG. 13 is a schematic cross-sectional view showing an example of theconfiguration of an image sensor according to the fifth embodiment ofthe present technology. The image sensor 1 of the drawing differs fromthe image sensor 1 described in FIG. 12 in that a light blocking pixel200 is further included. The light blocking pixel 200 is a pixel inwhich light from a subject is blocked, and is a pixel used for themeasurement of dark current, for example. Here, dark current is acurrent that flows into the pixel 100 regardless of incident light, andis a current that is superimposed on the image signal and is a cause ofnoise. Since the image signal generated by the light blocking pixel 200is a signal corresponding to dark current, dark current can be measuredby acquiring a signal from the light blocking pixel 200. The lightblocking pixel 200 is placed in an area other than the effective pixelarea of the pixel array unit 10. In the drawing, the light blockingpixel 200 is placed in a peripheral portion of the pixel array unit 10.

A light blocking film 210 for light blocking is placed in the lightblocking pixel 200 of the drawing. The light blocking film 210 may beconfigured with the same material as the light blocking line 111 of thelight polarizing unit 110, and can be formed simultaneously with thelight polarizing unit 110. Further, the drawing shows an example of thecase where the light blocking film 210 is connected to the lightblocking line 111. Further, the drawing shows an example of the casewhere the light blocking film 210 is connected to the interconnectionlayer 143 of the peripheral circuit unit 40 by the interconnection 33.

As described above, the light blocking film 210 is formed simultaneouslywith the light polarizing unit 110. Specifically, of a light blockingmaterial formed as one film, an ear portion on the outside of the lightpolarizing unit 110 may be used as the light blocking film 210. Inaddition, the configuration of the image sensor 1 is not limited to thisexample. For example, the light blocking film 210 may be placed in alayer different from the light polarizing unit 110, and the lightblocking film 210 and the light polarizing unit 110 may be formed byindividual processes.

Otherwise, the configuration of the image sensor 1 is similar to theconfiguration of the image sensor 1 described in the fourth embodimentof the present technology, and therefore a description is omitted.

As described above, according to the fifth embodiment of the presenttechnology, the manufacturing process of the image sensor 1 including alight blocking pixel can be simplified by forming the light blockingfilm 210 simultaneously with the light polarizing unit 110.

6. Sixth Embodiment

An imaging device in which the image sensor 1 is used will now bedescribed.

Configuration of Imaging Device

FIG. 14 is a diagram showing an example of the configuration of animaging device according to an embodiment of the present technology. Animaging device 9 of the drawing includes the image sensor 1, a verticaldriving unit 2, a column signal processing unit 3, and a control unit 4.

The vertical driving unit 2 generates a control signal of the pixelcircuit of the pixel 100. The vertical driving unit 2 transfers thegenerated control signal to the pixel 100 via a signal line 91 of thedrawing. The column signal processing unit 3 processes an image signalgenerated by the pixel 100. The column signal processing unit 3 performsthe processing of an image signal transferred from the pixel 100 via asignal line 92 of the drawing. The processing in the column signalprocessing unit 3 includes, for example, analog/digital conversion thatconverts an analog image signal generated in the pixel 100 to a digitalimage signal. The control unit 4 controls the entire imaging device 9.The control unit 4 generates and outputs control signals that controlthe vertical driving unit 2 and the column signal processing unit 3, andthereby controls the imaging device 9. The control signal generated bythe control unit 4 is transferred to the vertical driving unit 2 and thecolumn signal processing unit 3 by signal lines 93 and 94, respectively.

The image sensor 1 described in the first embodiment of the presenttechnology (the image sensor 1 in FIG. 1 ) may be used as the imagesensor 1 shown in the drawing. In this case, the signal transfer unit 20and the interconnection 30 described in FIG. 1 configure a part of thesignal lines 91 and 92. This similarly applies to the image sensor 1 inthe second embodiment and the third embodiment of the presenttechnology.

On the other hand, the image sensor 1 described in the fourth embodimentof the present technology (the image sensor 1 in FIG. 11 ) may be usedby replacing the image sensor 1, the vertical driving unit 2, and thecolumn signal processing unit 3 shown in the drawing. This is becausethe image sensor 1 in FIG. 11 includes the vertical driving unit 2 andthe column signal processing unit 3 as the peripheral circuit unit 40.In this case, the signal transfer unit 20 and the interconnection 30configure a part of the signal lines 93 and 94. This similarly appliesto the image sensor 1 in the fifth embodiment of the present technology.

Configuration of Pixel Circuit

FIG. 15 is a diagram showing an example of the configuration of a pixelcircuit according to an embodiment of the present technology. The pixel100 of the drawing includes a photodiode 103, a charge retention unit104, and MOS transistors 105 to 108.

The anode of the photodiode 103 is grounded, and the cathode isconnected to the source of the MOS transistor 105. The drain of the MOStransistor 105 is connected to the source of the MOS transistor 106, thegate of the MOS transistor 107, and one end of the charge retention unit104. The other end of the charge retention unit 104 is grounded. Thedrains of the MOS transistors 106 and 107 are connected to a powersupply line Vdd in common, and the source of the MOS transistor 107 isconnected to the drain of the MOS transistor 108. The source of the MOStransistor 108 is connected to the signal line 92. The gates of the MOStransistors 105, 106, and 108 are connected to a transfer signal lineTR, a reset signal line RST, and a selection signal line SEL,respectively. The transfer signal line TR, the reset signal line RST,and the selection signal line SEL configure the signal line 91.

The photodiode 103 corresponds to the photodiode configured by thephotoelectric conversion unit 132 and the semiconductor substrate 131described above in FIG. 2 . Further, the charge retention unit 104 andthe MOS transistors 105 to 108 configure the pixel circuit.

The MOS transistor 105 is a transistor that transfers a charge generatedby the photoelectric conversion unit 132 of the photodiode 103 to thecharge retention unit 104. The transfer of a charge in the MOStransistor 105 is controlled by a signal transferred by the transfersignal line TR. The charge retention unit 104 is a capacitor thatretains the charge transferred by the MOS transistor 105. The MOStransistor 107 is a transistor that generates a signal based on thecharge retained in the charge retention unit 104. The MOS transistor 108is a transistor that is controlled by a signal transferred by theselection signal line SEL and outputs the signal generated by the MOStransistor 107 as an image signal to the signal line 92. The MOStransistor 106 is a transistor that resets the charge retention unit 104by releasing the charge retained in the charge retention unit 104 to thepower supply line Vdd. The reset by the MOS transistor 106 is controlledby a signal transferred by the reset signal line RST, and is executedbefore a charge is transferred by the MOS transistor 105. Thus, thepixel circuit converts a charge generated by the photoelectricconversion unit 132 to an image signal.

7. Application Example to Endoscopic Surgery System

An embodiment of the technology according to the present disclosure (anembodiment of the present technology) can be applied to variousproducts. For example, an embodiment of the technology according to thepresent disclosure may be applied to an endoscopic surgery system.

FIG. 16 is a diagram illustrating an example of a schematicconfiguration of an endoscopic surgery system to which the technologyaccording to an embodiment of the present disclosure is applicable.

FIG. 16 illustrates a situation in which a surgeon (doctor) 11131 isusing an endoscopic surgery system 11000 to perform surgery on a patient11132 lying on a patient bed 11133. As illustrated in the diagram, theendoscopic surgery system 11000 is made up of an endoscope 11100, othersurgical instruments 11110, such as a pneumoperitoneum tube 11111, anenergy treatment tool 11112 or the like, a support arm apparatus 11120that supports the endoscope 11100, and a cart 11200 on which variousdevices for endoscopic surgery are provided.

The endoscope 11100 is made up of a lens tube 11101 having a region ofcertain length from the front end that is inserted into the body cavityof the patient 11132, and a camera head 11102 connected to the base endof the lens tube 11101. In the example illustrated in the diagram, anendoscope 11100 configured as a so-called rigid scope having a rigidlens tube 11101 is illustrated, but the endoscope 11100 may also beconfigured as a so-called flexible scope having a flexible lens tube.

On the front end of the lens tube 11101, there is provided an openinginto which an objective lens is fitted. A light source device 11203 isconnected to the endoscope 11100. Light generated by the light sourcedevice 11203 is guided up to the front end of the lens tube 11101 by alight guide extending inside the lens tube 11101, and is radiatedthrough the objective lens towards an observation target inside the bodycavity of the patient 11132. Note that the endoscope 11100 may be aforward-viewing scope, an oblique-viewing scope, or a side-viewingscope.

An optical system and an image sensor are provided inside the camerahead 11102, and reflected light from the observation target (observationlight) is condensed onto the image sensor by the optical system.Observation light is photoelectrically converted by the image sensor,and an electrical signal corresponding to the observation light, or inother words, an image signal corresponding to the observed image, isgenerated. The image signal is transmitted as RAW data to a cameracontrol unit (CCU) 11201.

The CCU 11201 is made up of components such as a central processing unit(CPU) and a graphics processing unit (GPU), and centrally controls theoperation of the endoscope 11100 and the display device 11202. Further,the CCU 11201 receives an image signal from the camera head 11102 andsubjects the image signal to various types of image processing fordisplaying an image based on the image signal, such as developmentprocess (demosaicing process), for example.

The display device 11202 displays an image based on the image signalsubjected to image processing by the CCU 11201, by control from the CCU11201.

The light source device 11203 is made up of a light source such as alight-emitting diode (LED), for example, and supplies the endoscope11100 with irradiating light when imaging the operating site.

An input device 11204 is an input interface with respect to theendoscopic surgery system 11000. Through the input device 11204, theuser is able to input various information and instructions into theendoscopic surgery system 11000. For example, the user inputsinstructions to change the imaging parameters of imaging by theendoscope 11100 (such as the type of irradiating light, themagnification, and the focus distance), and the like.

A treatment tool control device 11205 controls the driving of the energytreatment tool 11112 to cauterize or make incisions into tissue, sealblood vessels, or the like. The pneumoperitoneum device 11206 deliversgas into the body cavity through the pneumoperitoneum tube 11111 toinflate the body cavity of the patient 11132 for the purpose of securinga field of view for the endoscope 11100 and securing a workspace for thesurgeon. The recorder 11207 is a device capable of recording varioustypes of information related to surgery. The printer 11208 is a devicecapable of printing out various types of information related to surgeryin various formats, such as text, images, or graphs.

The light source device 11203, which supplies the endoscope 11100 withirradiating light when imaging the operating site, may be made up of awhite light source configured by an LED, a laser light source, or acombination of the two, for example. At this point, in the case in whichthe white light source is configured by a combination of RGB laser lightsources, the output intensity and output timing of each color (eachwavelength) can be controlled with high precision, and thus the whitebalance of the captured image can be adjusted with the light sourcedevice 11203. Also, in this case, by irradiating the observation targetwith laser light from each of the RGB laser light sources in atime-division manner, and controlling the driving of the image sensor ofthe camera head 11102 in synchronization with the irradiation timings,it is also possible to capture images corresponding to R, G, and B,respectively, in a time-division manner. According to such a method,color images can be obtained without providing the image sensor with acolor filter.

Also, the driving of the light source device 11203 may also becontrolled so as to change the intensity of the light to output everytime a certain amount of time elapses. By controlling the driving of theimage sensor of the camera head 11102 in synchronization with thetimings of changing the light intensity to acquire images in atime-division manner, and compositing the images together, it ispossible to generate a high dynamic range image without what are calledcrushed blacks and blown-out whites.

Additionally, the light source device 11203 may also be configured to beable to supply light in a certain wavelength band corresponding tospecial imaging. With special imaging, for example, the wavelengthdependency of light absorption by tissues of the body is utilized, andlight is radiated in a narrow band compared to the irradiating lightduring normal observation (that is, white light) to thereby imagecertain tissues, such as blood vessels in the superficial portion of themucous membrane, at a high contrast, also known as narrow band imaging(NBI). Alternatively, with special imaging, fluorescent observation thatobtains an image with fluorescent light by radiating excitation lightmay also be conducted. With fluorescent observation, it is possible toirradiate a body tissue with excitation light and observe fluorescentlight from the body tissue (autofluorescence observation), or locallyinject a reagent such as indocyanine green (ICG) into a body tissuewhile also irradiating that body tissue with excitation lightcorresponding to the fluorescence wavelength of the reagent to obtain afluorescent image, or the like. The light source device 11203 may beconfigured to be able to supply narrow-band light and/or excitationlight corresponding to such special imaging.

FIG. 17 is a block diagram illustrating an example of a functionalconfiguration of the camera head and the CCU illustrated in FIG. 16 .

The camera head 11102 includes a lens unit 11401, an imaging unit 11402,a driving unit 11403, a communication unit 11404, and a camera headcontrol unit 11405. Also, the CCU 11201 includes a communication unit11411, an image processing unit 11412, and a control unit 11413. Thecamera head 11102 and the CCU 11201 are mutually communicably connectedby a transmission cable 11400.

The lens unit 11401 is an optical system provided in the part thatconnects to the lens tube 11101. Observation light taken in from thefront end of the lens tube 11101 is guided up to the camera head 11102,and is incident on the lens unit 11401. The lens unit 11401 is made upof a combination of multiple lenses, including a zoom lens and a focuslens.

The imaging unit 11402 is configured with an image sensor. The number ofimage sensors configuring the imaging unit 11402 may be one (what iscalled a single-chip type), or may be plural (what is called amulti-chip type). In a case where the imaging unit 11402 is configuredwith a multi-chip type, a color image may be obtained by, for example,image signals corresponding to RGB, respectively, being generated by theimage sensors and these image signals being synthesized. Alternatively,the image sensor constituting the imaging unit 11402 includes a pair ofimage sensors for respectively acquiring image signals for the right eyeand the left eye corresponding to 3D display. By presenting a 3Ddisplay, the surgeon 11131 becomes able to grasp the depth of biologicaltissue at the operating site more accurately. Note that if the imagingunit 11402 has a multi-chip configuration, the lens unit 11401 likewiseis provided with multiple subsystems corresponding to each of the imagesensors.

Also, the imaging unit 11402 is not necessarily provided in the camerahead 11102. For example, the imaging unit 11402 may also be providedinside the lens tube 11101, directly behind the objective lens.

The driving unit 11403 is made up of actuators, and under control fromthe camera head control unit 11405, moves the zoom lens and the focuslens of the lens unit 11401 by a certain distance along the opticalaxis. With this arrangement, the magnification and the focus of theimage captured by the imaging unit 11402 may be adjusted appropriately.

The communication unit 11404 is configured with a communication devicefor transmitting and receiving various pieces of information with theCCU 11201. The communication unit 11404 transmits an image signalobtained from the imaging unit 11402 as RAW data to the CCU 11201 viathe transmission cable 11400.

Also, the communication unit 11404 receives from the CCU 11201 a controlsignal for controlling the driving of the camera head 11102, andprovides the control signal to the camera head control unit 11405. Thecontrol signal includes information related to imaging parameters, suchas information specifying the frame rate of the captured image,information specifying the exposure value during imaging, and/orinformation specifying the magnification and focus of the capturedimage, for example.

Note that the above imaging parameters such as the frame rate, theexposure value, the magnification, and the focus or the like may be setappropriately by a user, or may be set automatically by the control unit11413 of the CCU 11201 on the basis of the acquired image signal. In thelatter case, what are called an auto exposure (AE) function, an autofocus (AF) function, and an auto white balance (AWB) function areprovided in the endoscope 11100.

The camera head control unit 11405 controls the driving of the camerahead 11102 on the basis of a control signal from the CCU 11201 receivedvia the communication unit 11404.

The communication unit 11411 is made up of a communication device fortransmitting and receiving various information to and from the camerahead 11102. The communication unit 11411 receives an image signaltransmitted from the camera head 11102 through the transmission cable11400.

Also, the communication unit 11411 transmits a control signal forcontrolling the driving of the camera head 11102 to the camera head11102. The image signal or the control signal may be transmitted bytelecommunication or optical communication.

The image processing unit 11412 performs various pieces of imageprocessing on an image signal that is RAW data transmitted from thecamera head 11102.

The control unit 11413 performs various pieces of control concerning theimaging of the operating site etc. performed by the endoscope 11100 andthe display of a captured image obtained by the imaging of the operatingsite etc. For example, the control unit 11413 generates a control signalfor controlling the driving of the camera head 11102.

In addition, the control unit 11413 causes the display device 11202 todisplay a captured image on which the operating site or the like isreflected on the basis of the image signal subjected to image processingby the image processing unit 11412. At this point, the control unit11413 uses any of various types of image recognition technology torecognize various objects in the captured image. For example, bydetecting features such as the edge shapes and colors of objectsincluded in the captured image, the control unit 11413 is able torecognize surgical instruments such as forceps, a specific site of thebody, hemorrhaging, mist during usage of the energy treatment tool11112, and the like. When causing the display device 11202 to display acaptured image, the control unit 11413 uses the recognition results tooverlay various surgical assistance information onto the image of theoperating site. By surgical assistance information being overlaid fordisplay and presented to the surgeon 11131, the burden on the surgeon11131 can be reduced, and the surgeon 11131 can perform the surgeryreliably.

The transmission cable 11400 that connects the camera head 11102 and theCCU 11201 is an electrical signal cable supporting the communication ofelectrical signals, optical fiber supporting optical communication, or acomposite cable of the above.

At this point, in the illustrated example, communication is conducted ina wired manner using the transmission cable 11400, but communicationbetween the camera head 11102 and the CCU 11201 may also be conductedwirelessly.

Hereinabove, an example of the endoscopic surgery system to which anembodiment of the technology according to the present disclosure can beapplied is described. An embodiment of the technology according to thepresent disclosure can be applied to, of the configuration describedabove, the imaging unit 11402 of the camera head 11102. Specifically,the image sensor 1 of FIG. 1 can be used for the imaging unit 11402. Byapplying an embodiment of the technology according to the presentdisclosure to the imaging unit 11402, the surgeon (doctor) 11131 cangrasp the shape of the internal organs of the patient 11132 moreaccurately, and therefore the surgeon can observe the operating sitereliably.

In addition, although herein an endoscopic surgery system is describedas an example, an embodiment of the technology according to the presentdisclosure may be applied also to, for example, a microscopic surgerysystem and the like.

8. Application Example to Mobile Object

The technology (present technology) according to an embodiment of thepresent disclosure is applicable to a variety of products. For example,the technology according to an embodiment of the present disclosure isimplemented as devices mounted on any type of mobile objects such asautomobiles, electric vehicles, hybrid electric vehicles, motorcycles,bicycles, personal mobilities, airplanes, drones, ships, and robots.

FIG. 18 is a block diagram illustrating a schematic configurationexample of a vehicle control system which is an example of a mobileobject control system to which a technology according to an embodimentof the present technology is applicable.

A vehicle control system 12000 includes a plurality of electroniccontrol units connected via a communication network 12001. In theexample illustrated in FIG. 18 , the vehicle control system 12000includes a drive line control unit 12010, a body system control unit12020, a vehicle outside information detection unit 12030, a vehicleinside information detection unit 12040, and an integrated control unit12050. In addition, as functional configurations of the integratedcontrol unit 12050, a microcomputer 12051, an audio and image outputsection 12052, an in-vehicle network interface (I/F) 12053.

The drive line control unit 12010 controls the operation of devicesrelated to the drive line of the vehicle in accordance with a variety ofprograms. For example, the drive line control unit 12010 functions as acontrol device for a driving force generating device such as an internalcombustion engine or a driving motor that generates the driving force ofthe vehicle, a driving force transferring mechanism that transfers thedriving force to wheels, a steering mechanism that adjusts the steeringangle of the vehicle, a braking device that generates the braking forceof the vehicle, and the like.

The body system control unit 12020 controls the operations of a varietyof devices attached to the vehicle body in accordance with a variety ofprograms. For example, the body system control unit 12020 functions as acontrol device for a keyless entry system, a smart key system, a powerwindow device, or a variety of lights such as a headlight, a backuplight, a brake light, a blinker, or a fog lamp. In this case, the bodysystem control unit 12020 can receive radio waves transmitted from aportable device that serves instead of the key or signals of a varietyof switches. The body system control unit 12020 receives these radiowaves or signals, and controls the vehicle door lock device, the powerwindow device, the lights, or the like.

The vehicle outside information detection unit 12030 detects informationregarding the outside of a vehicle on which the vehicle control system12000 is mounted. For example, an imaging section 12031 is connected tothe vehicle outside information detection unit 12030. The vehicleoutside information detection unit 12030 causes the imaging section12031 to capture an image outside of the vehicle and receives thecaptured image. The vehicle outside information detection unit 12030 mayperform an object detection process or a distance detection process fora person, a vehicle, an obstacle, a sign, letters on a road, or the likeon the basis of the received image.

The imaging section 12031 is a light sensor that receives light andoutputs an electric signal corresponding to the amount of receivedlight. The imaging section 12031 can output the electric signal as animage or distance measurement information. In addition, the lightreceived by the imaging section 12031 may be the visible light or may benon-visible light such as infrared light.

The vehicle inside information detecting unit 12040 detects informationon the inside of the vehicle. The vehicle inside information detectingunit 12040 is connected, for example, to a driver state detectingsection 12041 that detects the state of the driver. The driver statedetecting section 12041 may include, for example, a camera that imagesthe driver. The vehicle inside information detecting unit 12040 maycompute the degree of the driver's tiredness or the degree of thedriver's concentration or determine whether the driver have a doze, onthe basis of detection information input from the driver state detectingsection 12041.

For example, the microcomputer 12051 can calculate a control targetvalue of the driving force generating device, the steering mechanism, orthe braking device on the basis of information acquired by the vehicleoutside information detecting unit 12030 or the vehicle insideinformation detecting unit 12040 on the inside and outside of thevehicle, and output a control instruction to the drive line control unit12010. For example, the microcomputer 12051 may perform cooperativecontrol for the purpose of executing the functions of an advanced driverassistance system (ADAS) including vehicle collision avoidance or impactreduction, follow-up driving based on the inter-vehicle distance,constant vehicle speed driving, vehicle collision warning, vehicle lanedeparture warning, or the like.

Further, the microcomputer 12051 can control the driving forcegenerating device, the steering mechanism, the braking device, or thelike on the basis of information acquired by the vehicle outsideinformation detecting unit 12030 or the vehicle inside informationdetecting unit 12040 on the areas around the vehicle, thereby performingcooperative control for the purpose of automatic driving or the likethat allows the vehicle to autonomously travel irrespective of anyoperation of a driver.

In addition, the microcomputer 12051 can output a control instruction tothe body system control unit 12020 on the basis of the informationregarding the outside of the vehicle acquired by the vehicle outsideinformation detection unit 12030. For example, the microcomputer 12051can control a head lamp in accordance with the position of a precedingvehicle or an oncoming vehicle detected by the vehicle outsideinformation detection unit 12030 and can perform cooperative control forthe purpose of anti-glaring such as switching a high beam to a low beam.

The audio and image output section 12052 transmits an output signal ofat least one of a sound and an image to an output device capable ofvisually or aurally notifying a passenger of the vehicle or the outsideof the vehicle of information. In the example of FIG. 18 , an audiospeaker 12061, a display section 12062, and an instrument panel 12063are exemplified as the output device. For example, the display section12062 may include at least one of an onboard display and a head-updisplay.

FIG. 19 is a diagram illustrating an example of an installation positionof the imaging section 12031.

In FIG. 19 , the vehicle 12100 includes imaging sections 12101, 12102,12103, 12104, and 12105 as the imaging section 12031.

Imaging sections 12101, 12102, 12103, 12104, and 12105 are positioned,for example, at the front nose, a side mirror, the rear bumper, the backdoor, and the upper part of the windshield in the vehicle compartment ofa vehicle 12100. The imaging section 12101 attached to the front noseand the imaging section 12105 attached to the upper part of thewindshield in the vehicle compartment chiefly acquire images of the areaahead of the vehicle 12100. The imaging sections 12102 and 12103attached to the side mirrors chiefly acquire images of the areas on thesides of the vehicle 12100. The imaging section 12104 attached to therear bumper or the back door chiefly acquires images of the area behindthe vehicle 12100. The image of the front side obtained by the imagingsections 12101 and 12105 is used chiefly to detect a preceding vehicle,a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, orthe like.

Additionally, FIG. 19 illustrates an example of the imaging ranges ofthe imaging sections 12101 to 12104. An imaging range 12111 representsthe imaging range of the imaging section 12101 attached to the frontnose. Imaging ranges 12112 and 12113 respectively represent the imagingranges of the imaging sections 12102 and 12103 attached to the sidemirrors. An imaging range 12114 represents the imaging range of theimaging section 12104 attached to the rear bumper or the back door. Forexample, overlaying image data captured by the imaging sections 12101 to12104 offers an overhead image that looks down on the vehicle 12100.

At least one of the imaging sections 12101 to 12104 may have a functionof acquiring distance information. For example, at least one of theimaging sections 12101 to 12104 may be a stereo camera including aplurality of image sensors or may be an image sensor that includespixels for phase difference detection.

For example, the microcomputer 12051 can extract a 3-dimensional objecttraveling at a predetermined speed (for example, 0 or more km/h) insubstantially the same direction as the vehicle 12100 as a precedingvehicle by particularly using a closest 3-dimensional object on a travelroad of the vehicle 12100 by obtaining a distance to each 3-dimensionalobject within the imaging ranges 12111 to 12114 and a temporal change inthe distance (a relative speed to the vehicle 12100) on the basis ofdistance information obtained from the imaging sections 12101 to 12104.Further, the microcomputer 12051 can set an inter-vehicle distance to beensured in advance before a preceding vehicle and perform automaticbrake control (also including follow-up stop control) or automaticacceleration control (also including follow-up oscillation control). Inthis way, it is possible to perform cooperative control for the purposeof automatic driving or the like that allows the vehicle to autonomouslytravel irrespective of any operation of a driver.

For example, the microcomputer 12051 can classify and extract3-dimensional object data regarding 3-dimensional objects as other3-dimensional objects such as motorcycles, normal vehicles, largevehicles, pedestrians, and electric poles on the basis of the distanceinformation obtained from the imaging sections 12101 to 12104 and canuse the other 3-dimensional objects to automatically avoid obstacles.For example, the microcomputer 12051 identifies obstacles around thevehicle 12100 as obstacles which can be viewed by a driver of thevehicle 12100 and obstacles which are difficult to view. Then, themicrocomputer 12051 can determine a collision risk indicating a dangerof collision with each obstacle and output a warning to the driver viathe audio speaker 12061 or the display section 12062 in a situation inwhich there is a collision possibility since the collision risk is setto be equal to or greater than a set value or can perform drivingassistance for collision avoidance by performing forced deceleration oravoidance steering iv via the drive line control unit 12010.

At least one of the imaging sections 12101 to 12104 may be an infraredcamera that detects infrared light. For example, the microcomputer 12051can recognize a pedestrian by determining whether there is thepedestrian in captured images of the imaging sections 12101 to 12104.The pedestrian can be recognized, for example, in a procedure in whichfeature points are extracted in the captured images of the imagingsections 12101 to 12104 serving as infrared cameras and a procedure inwhich a series of feature points indicating a contour of an object aresubjected to a pattern matching process to determine whether there isthe pedestrian. The microcomputer 12051 determines that there is thepedestrian in the captured images of the imaging sections 12101 to12104. When the pedestrian is recognized, the audio and image outputsection 12052 controls the display section 12062 such that a rectangularcontour line for emphasis is superimposed to be displayed on therecognized pedestrian. In addition, the audio and image output section12052 controls the display section 12062 such that an icon or the likeindicating the pedestrian is displayed at a desired position.

The example of the vehicle control system to which an embodiment of thetechnology according to the present disclosure can be applied has beendescribed above. An embodiment of the technology according to thepresent disclosure can be applied to the imaging section 12031 in theabove-described configuration. Specifically, the image sensor 1 of FIG.1 can be used for the imaging unit 12031. By applying an embodiment ofthe technology according to the present disclosure to the imaging unit12031, the shape of a road surface can be grasped more accurately, andtherefore safety during driving can be improved.

Lastly, the descriptions of the embodiments described above are examplesof the present technology, and the present technology is not limited tothe embodiments described above. Thus, for embodiments other than thosedescribed above, various alterations are possible in accordance with thedesign etc. without departing from the technical idea according toembodiments of the present technology, as a matter of course.

Additionally, the present technology may also be configured as below.

-   -   (1)    -   An image sensor, comprising:    -   a plurality of pixels, each pixel including:        -   a photoelectric conversion unit;        -   a light polarizing unit;        -   a pixel circuit; and    -   a plurality of signal transfer units, wherein at least a portion        of the light polarizing unit and at least a portion of the        signal transfer units are at a same layer of the image sensor.    -   (2)    -   The image sensor of (1), wherein the light polarizing unit        includes a plurality of light blocking lines having a pitch        narrower than a wavelength included in incident light.    -   (3)    -   The image sensor of (1) or (2), further comprising:        -   a semiconductor substrate, wherein the photoelectric            conversion unit is formed in the semiconductor substrate;            and        -   a first flattening film, wherein the light blocking lines            and the signal transfer units are formed on the first            flattening film.    -   (4)    -   The image sensor of (2) or (3), wherein the light blocking lines        are arranged at equal intervals, and wherein areas between        adjacent light blocking lines within a pixel are filled with        air.    -   (5)    -   The image sensor of claim any of (2) to (4), further comprising:        -   a protection film on a light incident side of the light            blocking lines, wherein the protection film seals the areas            between adjacent light blocking lines.    -   (6)    -   The image sensor of any of (2) to (5), wherein the light        blocking lines and the signal transfer units are formed from        aluminum.    -   (7) The image sensor of any of (1) to (6), further comprising:        -   an interconnection layer on a side of the semiconductor            substrate opposite a light incident side;        -   a plurality of via plugs; and        -   an interconnection included as part of each of the signal            transfer units, wherein the interconnection layer is            connected to each of the signal transfer units by a            respective via plug and a respective interconnection, and            wherein the image sensor is a back-side illumination image            sensor.    -   (8)    -   The image sensor of any of (1) to (6), further comprising:        -   an interconnection layer between a light incident side of            the semiconductor substrate and the light polarizing units            of the pixels, wherein the image sensor is a front-side            illumination image sensor.    -   (9)    -   The image sensor of any of (2) to (8), wherein the light        blocking lines are formed from a plurality of layers of        material, and wherein a first one of the plurality of layers of        material of the light blocking lines also forms the at least a        portion of the signal transfer units.    -   (10)    -   The image sensor of (9), wherein the first one of the plurality        of layers of material is a light reflecting layer, wherein a        second one of the plurality of layers of material is an        insulating layer, and wherein a third one of the plurality of        layers of material is a light absorbing layer.    -   (11)    -   The image sensor of any of (1) to (10), wherein a first pixel of        the plurality of pixels includes a light polarizing unit with        light blocking lines arranged in a first direction, and wherein        a second pixel of the plurality of pixels includes a light        polarizing unit with light blocking lines arranged in a second        direction.    -   (12)    -   The image sensor of (11), wherein the first direction is shifted        by 45 degrees compared to the second direction.    -   (13)    -   The image sensor of any of (1) to (12), wherein the pixels are        arranged in groups of four pixels, wherein each of the pixels in        a selected group has light blocking lines arranged in a        different direction.    -   (14)    -   The image sensor of (13), further comprising:        -   a plurality of color filters, wherein each of the pixels in            the selected group includes a color filter that transmits            light of a same color.    -   (15)    -   An image sensor, comprising:        -   a substrate;        -   a photoelectric conversion unit formed in the substrate;        -   a light polarizing unit on a light incident side of the            substrate; and        -   a signal transfer unit on the light incident side of the            substrate, wherein the light polarizing unit and the            photoelectric conversion unit are formed at a same layer of            the image sensor.    -   (16)    -   A method of forming an image sensor, comprising:        -   providing a substrate;        -   forming a first flattening film on a light incident side of            the substrate;        -   forming a light blocking material on the first flattening            film; and        -   forming a plurality of light blocking lines and at least a            first signal transfer unit from the light blocking material.    -   (17)    -   The method of (16), wherein forming the plurality of light        blocking lines and the at least a first signal transfer unit        from the light blocking material includes etching the light        blocking material.    -   (18)    -   The method of (17), wherein the etching is dry etching.    -   (19)    -   The method of any of (16) to (18), wherein the plurality of        light blocking lines and the at least a first signal transfer        unit are formed simultaneously.    -   (20)    -   The method of any of (16) to (19), wherein the light blocking        material is a metal.    -   (21)    -   An image sensor including:    -   a light polarizing unit configured to transmit light in a        specific light polarization direction out of incident light;    -   a pixel configured to generate an image signal corresponding to        the light transmitted through the light polarizing unit; and    -   a signal transfer unit formed simultaneously with the light        polarizing unit and configured to transfer either of the image        signal and a control signal that controls generation of the        image signal.    -   (22)    -   The image sensor according to (21),    -   in which the light polarizing unit is configured with a wire        grid.    -   (23)    -   The image sensor according to (21) or (22),    -   in which the signal transfer unit is configured with a pad.    -   (24)    -   The image sensor according to any of (21) to (23),    -   in which a part of the signal transfer unit is formed        simultaneously with the light polarizing unit.    -   (25)    -   The image sensor according to any of (21) to (24), further        including:    -   a protection film configured to protect the light polarizing        unit,    -   in which the signal transfer unit is configured by removal of        the protection film formed in an area adjacent to a surface of        the signal transfer unit on which the light is incident.    -   (26)    -   The image sensor according to any of (21) to (25), further        including:    -   an interconnection formed simultaneously with the light        polarizing unit and configured to connect the signal transfer        unit and the pixel together.    -   (27)    -   The image sensor according to any of (21) to (26), further        including:    -   a connection unit formed simultaneously with the light        polarizing unit and configured to connect the signal transfer        unit and the light polarizing unit together.    -   (28)    -   A method for manufacturing an image sensor, the method        including:    -   simultaneously forming    -   a light polarizing unit configured to transmit light in a        specific light polarization direction out of incident light and    -   a signal transfer unit configured to transfer either of an image        signal generated in accordance with the light transmitted        through the light polarizing unit and a control signal that        controls generation of the image signal    -   on a substrate on which a pixel configured to perform generation        of the image signal is formed.

REFERENCE SIGNS LIST

-   -   1 image sensor    -   2 vertical driving unit    -   3 column signal processing unit    -   4 control unit    -   9 imaging device    -   10 pixel array    -   20 signal transfer unit    -   21 first signal transfer unit    -   22 second signal transfer unit    -   30, 33 interconnection    -   40 peripheral circuit unit    -   91 to 94 signal line    -   100 pixel    -   110 light polarizing unit    -   111 light blocking line    -   112 area    -   113 light absorbing layer    -   114, 141 insulating layer    -   115 light reflecting layer    -   121 on-chip lens    -   122 color filter    -   123 second flattening film    -   124 protection film    -   125 first flattening film    -   131 semiconductor substrate    -   132 photoelectric conversion unit    -   142, 143 interconnection layer    -   200 light blocking pixel    -   210 light blocking film    -   11402, 12031, 12101 to 12105 imaging unit

The invention claimed is:
 1. An image sensor, comprising: a plurality ofpixels, each pixel including: a photoelectric conversion unit; a lightpolarizing unit, wherein the light polarizing unit includes a pluralityof light blocking lines; and a pixel circuit; and a plurality of signaltransfer units, wherein the plurality of signal transfer units arearranged in a peripheral portion of the image sensor.
 2. The imagesensor of claim 1, wherein the plurality of light blocking lines have apitch narrower than a wavelength included in incident light.
 3. Theimage sensor of claim 1, wherein at least a portion of the lightpolarizing unit and at least a portion of the plurality of signaltransfer units are at a same layer of the image sensor.
 4. The imagesensor of claim 1, wherein the light polarizing unit and thephotoelectric conversion unit are formed at a same layer of the imagesensor.
 5. The image sensor of claim 1, further comprising: a firstflattening film, wherein the plurality of light blocking lines and theplurality of signal transfer units are formed on the first flatteningfilm.
 6. The image sensor of claim 1, wherein the plurality of lightblocking lines are arranged at equal intervals, and wherein areasbetween adjacent light blocking lines within a pixel are filled withair.
 7. The image sensor of claim 6, further comprising: a protectionfilm on a light incident side of the plurality of light blocking lines,wherein the protection film seals the areas between the adjacent lightblocking lines.
 8. The image sensor of claim 1, wherein the plurality oflight blocking lines and the plurality of signal transfer units areformed from aluminum.
 9. The image sensor of claim 1, furthercomprising: an interconnection layer on a side of a semiconductorsubstrate opposite a light incident side; a plurality of via plugs; andan interconnection included as part of each of the plurality of signaltransfer units, wherein the interconnection layer is connected to eachof the plurality of signal transfer units by a respective via plug and arespective interconnection, and wherein the image sensor is a back-sideillumination image sensor.
 10. The image sensor of claim 1, furthercomprising: an interconnection layer between a light incident side of asemiconductor substrate and the light polarizing unit of each pixel,wherein the image sensor is a front-side illumination image sensor. 11.The image sensor of claim 1, wherein the plurality of light blockinglines are formed from a plurality of layers.
 12. The image sensor ofclaim 11, wherein a first one of the plurality of layers is a lightreflecting layer, wherein a second one of the plurality of layers is aninsulating layer, and wherein a third one of the plurality of layers isa light absorbing layer.
 13. The image sensor of claim 1, wherein afirst pixel of the plurality of pixels includes a first light polarizingunit with first light blocking lines arranged in a first direction,wherein a second pixel of the plurality of pixels includes a secondlight polarizing unit with second light blocking lines arranged in asecond direction, and wherein the first pixel is adjacent to the secondpixel.
 14. The image sensor of claim 13, wherein the first direction isshifted by 45 degrees compared to the second direction.
 15. The imagesensor of claim 1, wherein the plurality of pixels are arranged ingroups of four pixels, wherein each pixel in a respective group haslight blocking lines arranged in a different direction.
 16. The imagesensor of claim 15, further comprising: a plurality of color filters,wherein each pixel in a respective group includes a color filter thattransmits light of a same color.
 17. The image sensor of claim 1,further comprising: a light blocking pixel used for measurement of darkcurrent.
 18. The image sensor of claim 1, further comprising: aperipheral circuit unit.
 19. The image sensor of claim 1, wherein theimage sensor comprises a front-side illumination image sensor.
 20. Animage sensor, comprising: a substrate; a photoelectric conversion unitformed in the substrate; a light polarizing unit on a light incidentside of the substrate wherein the light polarizing unit includes aplurality of light blocking lines; and a signal transfer unit on thelight incident side of the substrate, wherein the signal transfer unitis arranged in a peripheral portion of the image sensor.